Commitments (Details)	9 Months Ended
	Sep. 30, 2016 Per_Mcfe Partnership
Oct 2016 - Apr 2018 [Member]
Other Commitments [Line Items]
Capacity levels (Dekatherms per day) | Partnership	4,450
Oct 2016 - Apr 2018 [Member] | Minimum [Member]
Other Commitments [Line Items]
Demand charges (in dollars per dekatherm)	0.20
Oct 2016 - Apr 2018 [Member] | Maximum [Member]
Other Commitments [Line Items]
Demand charges (in dollars per dekatherm)	0.65
May 2018 - May 2020 [Member]
Other Commitments [Line Items]
Capacity levels (Dekatherms per day) | Partnership	2,150
Demand charges (in dollars per dekatherm)	0.20
Jun 2020 - May 2036 [Member]
Other Commitments [Line Items]
Capacity levels (Dekatherms per day) | Partnership	1,000
Demand charges (in dollars per dekatherm)	0.20